Etching-machine



W. s. EATON. ETCHING MACHINE. APPLICATNJNi FILED JAN.24, |919. RENEWED APR. 23, 1920- 1,$.'*}41,'739.l

Patented June 1, 1920.

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w.s. EATON.

ETCHING MACHINE. APPLICATIQN FILED 1AN.24, 1919. nENEwr-:D APR.

Patente-M1111@ 1, 1920.

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ETCHING-IVIACHINE.

Specification of Letters Patent.

Patented J une 1, 192,0.

Application filed January 24, 1919, Serial No. 272,842. Renewed April 23, 1920. Serial No. 376,172.

To all whom it may concern Be it known that l, WILLIAM S. EATON, a citizen of the United States, residing at Sag Harbor, in the county of Suffolk and State of New; Yorlnhave invented certain new and useful Improvements in Etching- Machines, of which the following is a speciparing printing surfaces for acid etching.

lnmachines of the character to which my invention relates, the design to be etched is mechanically reproduced vby a pantograph mechanism from suitable patterns, this mechanism being capable of various adjustments to control the scale of the reproduction, to extend or condense the reproduction as compared with the pattern, or to pitch the reproduction forwardly or backwardly. The changes` in the design resulting from such adjustments, in no wise alter the quantity of movement of the tracing stylus, and thus permit variation in the reproduced design while using the same pattern.

A machine made in accordance with my invention is not designed to remove any portion of the printing surface, but'merely to act upon the wax, or other resist,`upon said surface, in a manner to expose portions of the surface to permit the acid to act thereon.

ln using a machine made lin accordance with my invention, it is essential to frequently remove the work tool or point from the printing surface, particularly when portions of the design being produced, are disconnected from other portions thereof, and to permit inspection of thework being done. rl`he nature of this work requires little or no pressure from the work tool` or point upon the printing surface, gravity being relied upon to secure the desired penetration of the wax, or other resist, by said tool or point.

I have discovered that while a machine is in use, there is no tendency ofthe 'work tool or point to scratch the printing surface beneath the wax, or other resist, but that there is a tendency of said work tool or point to mar this surface when the work tool or point is first brought into engagement therewith, resulting in the formation of small dots upon said surface. As `a consequence, the depth of the etched portion of the design is greater where these dots are formed, and many minute, darker spots occur in the imprints made from such surfaces. .This

condition is particularly true vwhen the mai the work, or setl in relation thereto by means` of a micrometer screw mechanism, cannot be used in removing the wax, or other-resist, from printing surfaces to be vacid etched. v

lWith these conditions yin mind, I have produced a machine wherein the work tool or point will descend by gravity toward the printing surface, this descentbeing controlled by an automatically acting resistance device, in a manner to permit the tool or point to penetrate the wax, or other resist,l

and yet gather so little momentum as to cause it to come into contact with vthe printing surface, with an impact sufficiently light to avoid, or with the absence ofvsuch a forceful impact to cause, even the most minute penetration of this surfacethereby. This device is so constructed as to permit it to be adjusted with great nicety and precision, while permitting the rapid removal of the tool from the printing surface.

l/Vhile the field of greatest utility of a machine made in accordance with my invention, is its use in preparing lithographie' stones, l so construct it that it may be readily 'so set as to be adapted for use upon metal plates.

The invention consists primarily in a machine of the character described, embodying therein a support for a work tool or point, a tool carried thereby, a work bed, means adapted to impart relative universal movement upon a single plane, to said support and said work bed, a member operative upon said support to move it away from said work bed, means whereby said port, to permit said support to descend by gravity toward said work bed and bring said work tool or point into operative engagement with the printing surface, and a resistance device operative upon said support controlling` the descent thereof under gravity, whereby sufhciently forceful impact of said work tool or point with the printing surface, to mar same, is prevented;

and in such other novel features of construction and combination f parts as are hereinafter set forth and described, and more particularly pointed out in the claims hereto appended.

Referring to the drawings,

Figure 1 is a front elevation of the upper portion of a machine embodying my invention;

Fig. 2 is a plan view thereof, upon a larger scale, with a portion of the work tool or point support broken away;

Fig 3 is a vertical section 0f the head of the machine; and

Fig. 4 is a detailed view of a portion of the resistance mechanism.

Like numerals refer to like parts throughout the several views.l

In the embodiment of my invention shown in the drawings, 1 indicates the main frame of the machine, upon the table 2 of which is mounted a suitable holder 3 for the pattern. Supported by the table 2 is a column 4 having a head 5 provided with suitable ball cups 6, 7 and 8. Carried by the head is a block 9 to which is permanently secured a shelf 10 upon which the work bed 11 is adjustably mounted so as to have movement either laterally of the machine, or longitudinally thereof. This adjustability of the work bed 11 is secured by means of a carriage 12 mounted in longitudinally extending tracks 13 upon the shelf 10, the work bed proper 11 being slidably mounted by means of the dove tail slide connection 14, between it and said carriage 12, to have movement laterally of the machine upon said carriage. For imparting movement of the carriage 12 and the work bed 11 mounted thereon longitudinally of the machine, l employ a rack 15 carried b y the shelf 10, with which the gear 16 upon the shaft 17, meshes, said shaft being mounted in suitable bearings upon the carriage 12. Also mounted in the carriage 12 is a shaft 18 carrying a pinion 19 meshing with a rack 20 upon the underside of said work bed. thus permitting the movement of said work bed laterally of the machine upon the carriage 12.

Along the front edge of the work bed 11 is a plate 21 between which, and a movable dog 22, the material of the printing surface is adapted to be held. Said dog 22 is slidably mounted in a groove 23 upon said work bed, being adjustably mounted upon the actuating rod 24, by means of coperating screw threads thereon, and upon said rod. Said dog is brought into engagement with the material of the printing surface bydme'ans of the spring 25 acting upon said ro In the accompanying drawings l have illustrated the printing surface upon which work is to be done, as consisting of a lithographie stone 26, although as 'will more fully appear hereinafter, the machine is capable of such adjustment as to be used upon other types of printing surfaces, such as copper plates, or aluminum or zinc plates used in the lithographie art. Throughout the specification l have referred to the material upon which work is to be done as a printing surface, or as material having a printing surface, it being understood that these terms are employed to distinguish the kind of work which the machine is particularly designed to do, from other kinds of` work, such as engraving uponjewelry.

Positioned above, and projecting over, the work bed 11, is an arm 27, or other suitable support for the work tool or point 28, this arm, or other support, being adapted to have movement toward, or from, the work bed 11, tol bring the work tool or point into engagement with the printing surface 26, or out of` engagement therewith.

In order to reproduce the design upon the printing surface, it is necessary that the work bed 11 and the arm, or other support, 27, for the work tool or point 28, have relative universal movement upon a` single plane, this result being secured in the form of the invention shown, by imparting such movement to the arm, or other support, 27, while maintaining the work bed 11 stationary. This construction is particularly adaptable for work upon lithographic stones, because of the liability of the moving inertia of parts to develop imperfections in a reproduction when a heavy weight has to be moved by the actuating means for the movable member.

In the embodiment of the invention shown in the drawings, the arm 27 is carried by a carriage 29 having inverted ball cups 30, 31 and 32 oppositely disposed to the ball cups 6, 7 and 8 respectively, and supported therefrom by means of the bearing balls 33, 34 and 35. The diameter of each of said balls is considerably smaller than that of the coperating bearing cups, to permit the desired range of movement of said carriage.

Carried by the carriage 29 is a yoke 36 in which is pivotally mounted a frame 37, the aXis of the pivots of said frame being parallel with the printing surface 26. Said frame has a forwardly extending arm 38, the end of which s shaped to conform to the upper portion of the arm 27, said arm 38, intermediate the end thereof and the yoke 36, being provided with a ring n 39 through which the arm 27 passes, said ring being acted upon by a screw 4() carried by the arm 38 in a manner to draw the arm 27 into engagement with the end of the arm 38, and thus hold it firmly in position with relation to said frame, while permitting said arm 27 to be loosened in its mounting in va manner to permit it to be adjusted axially thereof, to vary the position of the work tool or point 28 in relation to the printing surface. rIhe Vframe 37V is so formed adjacent the point of its pivotal support, as to engage the arm 27, thus causing the actuation of the screw 40, to move said arm toward, or from, two bearing surfaces upon said frame, and upon the arm 88, between which surfaces the ring 39 1s located. y

lSince "the arm, or other support, 27, projects radially of the axis lof support of the frame 37, there is a normal tendency of said -arm 27 to drop Aby gravity, so as `to bring the work tool or point 28 into engagement with the printing surface 26. To place the movements of the armr 27 under the control of the operator, I provide a supporting bar 41, upon which the arm 27 normally rests, and by which it is normally vheld out of engagement with the printing surface. rlhis bar is of suiiicient length to permit the desired range of movement of the arm 2T. Said bar 41. is mounted'in a suitable bearing in the head 5, being normally thrust toward the arm 2T by means of the spring 42 seated between said head 5 and a collar 43, upon the stem 41a supporting said bar, and also by means of the actuating mechanism for said bar which consists of a pull rod 44, a crank shaft 45, acted upon by a torsion spring 46, and a link 47 acting upon said crank shaft, and connected to a foot treadle, or any other desired mechanism not shown, for actuating p said bar.

The springs 42 and 46, as heretofore stated, have a normal tendency to thrust the bar 4l upwardly in a manner to move the arm 2,7 and the work tool or point 28 carried thereby, away from the printing surface 2G. l/Vhen it is desired to bring said work Uool or point into engagement with the printing surface, it is merely necessary to draw the har 4i downwardly against the tension of said springs, thus permitting the arm 27 to descend by gravity. The movement of the bar 4l, however, is, in the actual use of the machine, very rapid, so that the arm 27, even though its movement is not great acquires suiiicient momentumy to cause a sufhciently heavy impact of the work tool or point 28, with the printing surface, rto result in its not only penetrating the waX, or other resist, upon said surface, but by reason sequent etching operation. 1f the material of the printing surface be suiciently hard to resist penetration of the work tool or point, likelihood of thus marring the plate is somewhat remote, but if the surface be soft, like in lithographie stones, or even in .Zinc or aluminum lithographic plates, this marringwill occur substantially every time the work tool or point is brought into engagement with the printing surface, although the likelihood of marring is very much less with the metalsurfaces than with the lithographie stones. In order to permit the use of the machine for reproducing designs upon lithographic stones, or other printing surfaces apt to be marred as a result of the impact of the work tool or point 28 therewith, I provide a resistance or retard device operativeupon the arm 27, or other support for the work tool, which will have the effect of controlling the rate of movement of said arm, or other support, in

a manner to prevent the accumulation of force from the moving inertia of said arm, or other support, suflicient to cause the impact of the work tool or point with the printing surface, to more than penetrate the wax, or other resist, thereon. In fact, the penetration of said wax, or other resist, will result from the dead load of the arm, or other support, and the work tool or point carried thereby, instead of as a result of the force of the impact of the work tool or point therewith. I

This resistance device comprises a cylinder 48 having slidably mounted therein a cup-shaped plunger 49, carrying a rod 50, provided with an adjustable stop 5L Projecting from, and movable with, the frame 3T, is a forked arm 52, straddling the rod 50, and adapted to engage beneath the stop 5l. The cylinder 48 is partially filled with a suitable fluid suchI as oil, or, if` desired, mercury could be used, the purpose of which is to seal the lower edgeof the plunger 49, and retard the upward movement thereof.

Carried by the plunger 49 is a vent valve consisting of a casing 53, having a valve seat toward the bottom thereof, and a ball valve 54 mounted within said casing and upon said seat, said casing being` provided with a reduced neck 55 having a port therethrough communicating with the interior of the plunger 49. Also carried by the plunger 49 is a regulating device consisting of a1 casing 56 having openings therein commu- CIK nicating with atmosphere, and a screw actuated needle valve 57 controlling a port in the neck 5S in communication with the interior of said plunger 49. By this construction the rapid descent of the plunger 49 is permitted, as a result of the free venting action through the valve casing 53, and the capability of movement of the arm 52 away from the stop 51, while the upward movement thereof may be exactly controlled by the proper regulation of' the volume of air admitted within the plunger 49, through the regulating device.

To permit adjustment of the machine so as to adapt it for work either upon lithographic stones, or upon thinner printing surfaces, I so support the yoke 36 and the bar 40 that they may be adjusted toward, or from, the carriage 29, so as to space the arm 27 closer, or more remote from the work bed 11, according to the thickness of the material of the printing surface upon which the work is to be done.

In the form of the invention shown, the stem 41a supporting the rod 41, is made in two sections, one of Which, as 59, is telescopically mounted in relation to the other, this section being set in its adjusted position by means of the set screw 60, or in any other desired manner. The yoke 36 is mounted in a distance block 61 by means of the set screw 62, said distance block being removably mounted in the carriage 29, so that by a removal of this block, the stem ot the yoke 36 may be mounted directly upon the carriage by means of the screw 63. rIhe stop 51 being adjustably mounted upon the rod 50, said stop may be adjusted to conform with other adjustments in the machine.

The carriage 29 may be actuated in conformity with the pattern, by any desired mechanism, insuring Athe universal movement of said carriage upon a single plane. This mechanism in the form of the invention shown, comprises a transmitter arm 64 having a tracing point or stylus 65 slidably mounted in the lower end thereof, so as to follow the pattern irrespective of the oscillations of said arm 64. This arm is mounted in a yoke 66 by means oi shoes 67, embracing an angular portion of said arm 64, and pivotally mounted in a ring 68, which ring in turn is pivotally mounted by means of suitable pivot screws 69 in said yoke 66. The axes of the pivot screws 69 and of the pivots of the shoes 67, extend at right angles to each other. The yoke 66 is carried by a sleeve 7 0 adjustably mounted upon the column 4, the adjustment of this sleeve being secured by the rack and pinion mechanism 71.

The ring 68 is provided with diametrically opposite lugs 72, having bearings therein as indicated in dotted lines in Fig. 3, each of which bearings is adapted to be engaged by the pivot screws 69 to permit the adjustment of the machine to either condense, or extend, the reproduction, or vary the width thereof with relation to other dimensions, the height remaining constant at any scale of adjustment.

The upper end of the arm 64 is pivotally mounted in a ring 73, which ring in turn is pivotally mounted upon the carriage 29, the axes of the pivots connecting said ring with said carriage extending at right angles to the pivots connecting the transmitter arm with said ring.

To permit the adjustment of the machine :tor tilting the reproduction, or giving it a forward or a backward inclination, the yoke 66 is connected with the collar 7 O by means ol the pivot screw 74, the axis of which pivot extends at right angles to the axis of the column 4. To permit the setting of the collar 70 in any adjusted position, I split this collar as shown in Fig. 3, and provide a clamp screw by means of which the collar may be clamped upon the column 4.

The operation of the herein described machine is substantially as follows In pantographic engraving machines of the type where the work bed or plate receives universal movement, the right or left of the design, and the top and bottom of the pattern, bear the same relation in the reproduction. In other words, with this type or" machine, the reproduction, except as to the scale, coincides with the pattern. In the type of machine, however, in which the work tool or point 'has movement in relation to the work bed, the latter being immovable, everything is reversed in the reproduction, the right becoming the left, the left the right, the bottom the top, and the top the bottom. n

The operation of the two types of machines, however, is substantially identical, this variance in the character of the reproduction necessitating merely a proper provision therefor in the production of the pattern.

Where letters are to be reproduced, and the type oi machine to which my invention relates is largely used for such reproductions, the machine employing a movable work bed, requires a pattern wherein the characters are like ordinary types and arranged in the same manner, the characters, however, being depressed instead oi raised.

In a machine in which the work tool or point has movement, however, it is necessary to use a pattern such as is used in the other type of machine, set upside down, so as to bring the right oi' the pattern to the left of the machine, unless the work upon the printing surface is to appear upside down. In this type of machine, however, the letters in reverse will read from left to right to insure their proper positioning in the reproduction. l/Vhen these conditions are complied with, the letters of the reproduction will be properly placed upon the printing surface, hut in the reverse, so as to insure a proper imprint therefrom.

Thepatternis placed upon the holder 3 within the operative range of the stylus 65. In adjusting a machine to control the scale of reproduction, the screw 75 isv released, and the collar 70 moved by means of the rack and pinion mechanism 71, towardor from the tracing stylus 65, thus varying the fulcrum point affordedby the bearing shoes 67 and the pivot screws 69. If the movement be toward said stylus, the length of the portion of the arm between said'fulcrum point and said stylus will be diminished, and the length of the portion of said arm between said fulcrum point and the carriage 29 will be increased, thus increasing the scale of reproduction, but if the movement be away from said stylus, this condition will be reversed, and the scale of the reproduction will be reduced. By dropping the ring 68 with relation to the pivot screws 69, the fulcrum of the shoes 67 only, will be varied, thus increasing the leverage at which the arm 64 acts, as to the movements of the carriage laterally of the machine, the leverage at which it acts for imparting movement to the carriage longitudinally of the machine, remaining the same. This extends the letters. If, however, the ring 68 be reversed and raised with relation to said pivot screws, the leverage at which the arm 64 acts upon the carriage laterally of the machine, will be reduced, while the effective leverage, longitudinally of the machine, will remain the same, so that the letters will he condensed. This raising or lowering of the ring 68 is accomplished. by means of the lugs 72. l

Tf the yoke 66 be tilted to the left (Fig.

ll upon the pivot screw 74, the axes of the' pivots 69 will extend obliquely to the axis of the arm 64, so that a longitudinal oscillation of said arm will result in a slight movement of the carriage to the-left at one side of the center of the pattern, and to the right at theother side of said center, simultaneously with yits longitudinal movement, thus tilting the reproduction slightly yto the right. If the yoke 66 be tilted. to thefright, the movement of the carriage 29 will be opposite to that above described, and the reproduction will be tilted to the left. The amount of tilting of the reproduction will be `governed by the angle of obliquityof the axes of the pivots 69 in relation to the axis of the arm 64, the greater the angle of obliquity, the greater the tilt of the` reproduction, I have found it necessary, to secure a desirable effect when tilting letters, to release the screw 40 and adjust the support or arm 27 so as to bringthe work tool or point 28 closer to the frame 37. i

As the tracing point or stylus is moved over the pattern, corresponding movement,

to an extent, however, determined by the adjustment of the machine, will be imparted to the carriage 29, but inthe reverse direction, the transmitter arm 64 acting as a lever, one arm of which carriesthe ,stylus and the other arm of which is connected by a f to said printing surface, portions -of the ,i

wax, or other resist, conforming to the vdesign to be etched, will be removed from said surface, so as to expose the metal through said wax, or other resist. The design of the pattern is thus reproduced upon said printing surface, but upon a different scale.

When it is desired to bring the work tool or point 28 into` engagement with said printing surface 26, it is merely necessary toy rock the shaft 45 against the tension ofthe spring 46, thus exerting a j downward ,pull upon the link 44 to draw the stem 41a downwardly against the tension of the spring` 42, and move the supporting bar 41 away from the arm 27. This movement of the bar 41 permits gravity toact upon the arm 27,and

were it not for the resistance or retard device, said arm would follow the .bar 41 and come to rest only with the impact `.of the tool 28 with the printing surface. This impact, as stated above, would have the effect of forming a dot upon this surface, and since, in the :operation of the machine, it is not feasible to control the rate of movement of the arm 27 through the bar 41, said re- A sistance or retard device is essential to avoid this forceful impact and the resultant marring of 'said surface. With the rocking `movement of the frame 37, with the descent y of the arm 27, the weight of this arm will move the forked arm' .52 upwardly, thus, through the stop 5 1 androd 50, raising the plunger or bell 49.- The ball valve 54 normally closesthe port 55, so. that the upward movement of said plunger has a tendency v to develop a subatmospheric pressure inthe Aupper portion thereof above the level of the fluid in the cylinder 48, and develop a resistance to the movement of this plunger, which work tool or point 28 with` the printing surface, were it not for the regulating device, which will gradually admit air into said plunger in volume suficient to tend to bring would actually prevent the Contact ofthe the pressure therein to atmosphere, and thus permit a continuance of this movement. 'By regulating the volume of the air flowing through the port 58 by means of the needle valve 57, the rate of movement of the plunger may be so controlled as to permit the desired movement of the arm 27, but have this movement so gradual that the work tool or point will come to rest upon the printing surface after penetrating the wax, or other resist, without any such impact as will mar the plate. In fact the penetration of the wax, or other resist, will be by a gradual movement.

The extent of movement of the arm 27 is not great, so that while it is very gradual, there is no such relay asy will interfere with the capacity of the machine. While the machine is at work, the atmospheric pressure within the plunger or bell 49, will avoid any tendency of the resistance or retard mechanism to raise the point from the work, the weight of the arm 27 holding this plunger 49 in the raised position.

When it is desired to raise the work tool or point from the printing surface, it is merely necessary to release the shaft 45, thus permitting the springs 46 and 42 to raise the supporting arm 27, the forked arm 52 moving away from the stopv51, so as to relieve the plunger from the load of said arm. Immediately that said plunger is re lieved from this load, the dead weight thereof will cause the plunger to descend in the piston 48, the air within said plunger being vented through the port 55 and about the valve454 with suiicient rapidity to permit the plunger to quickly descend so as to be in position preparatory to the next actuation of the bar 41 to bring the work tool or point into engagement with the printing surace.

The rack and pinion mechanism 15, 16 and 17 is used for positioning the printing surface so as to secure the proper line spacing of the reproduction, while the rack and pinion mechanism 18, 19 and 20 is used to impart a lateral movement to said surface, to secure the proper spacing of the letters in a line. i

Of course the weight of the arm 27 between theframe 37 and the work tool or point 28 must be suflicient to overbalance the portion of the arm upon the other side of the pivots of said framethe arm 52 and the plunger or bell 49 and its appurtenances.

I believe it to be broadly new to provide a machine of this character wherein the movement of the support or arm for the work tool or point is so controlled as to avoid the marring of the printing surface, as a result of the impact of the work tool or point therewith, thus adapting the machine for use upon lithographie stones or other material, the printing surface of which may be marred even with a slight impact of the work tool or point therewith. l

It is not my intention to limit the invention to the details of construction shown in the accompanying drawings, it being apparent that such may be varied without departing from the spirit and scope of the invention.

Having described the invention what I claim as new, and desire to have protectec by Letters Patent, is

1. A machine of the character described, embodying therein a movable support for a Work tool or point, a work tool or point carried thereby, a work bed, means adapted to impart relative universal movement upon a single plane, to said support and said work bed, a member operative upon said support to move it away from said work bed, means whereby said member may be moved away from said support to permit said support to descend by gravity toward said work bed, and bring said work tool or point into opn erative engagement with a printing surface upon said work bed, and a resistance device operative upon said support to control the descent thereof under gravity, whereby sufliciently forceful impact of said work tool or point with the printing surface, to mar same, is prevented. 95

2. A machine of the character described, embodying therein a movable support for a work tool or point, a work toel or point carried thereby, a work bed, means adapted to impart relative universal movement upon a single plane, to said support and said work bed, a member operative upon said support to move it away from said work bed, means whereby said member may be moved away from said support to permit said support to rdescend by gravity toward said work bed, and bring said work tool or point into operative engagement with a printing surface upon said work bed, and a resistance device operative upon said support to control the descent thereof under gravity, whereby auflicifently :forceful impact of said work tool or point with the printing surface, to mar same, is prevented, including therein. a calibrating device whereby the rate of movement of said support may be regulated.

3. In a machine of the character described, embodying therein a work bed, a pivotal support for a work tool or point projecting over the work bed, the axis of the pivots of said support being parallel with the surface of said work bed, a worktool or point carried thereby, means adapted to impart relative universal movement upon a single plane to said support and said work 125 bed, a member operative upon said support to move it away from said work bed, means whereby said member may be moved away from said support to permit said support te move under gravity and bring said work 130 a printing surface upon said work bed, a resistance device, a stop carried thereby, and an arm projecting radially of the airis of the pivots of said support projecting beneath said stop, so as to operatively engage saine, whereby said resistance device is operative upon said support to control the descent thereof under gravity and avoid a sufficiently forceful impact of said work tool or point with the printing surface, to mar same, and said support may be moved away from said work bed, independently of said resistance devis ll. A machine of the character described, embodying` therein a movable support for a work tool or point, a work tool or point carried thereby, a work bed, means adapted to impart relative universal movement upon a single plane, to said support and said work bed, a member operative upon said support to move it away Jfrom said work bed, means whereby said member may be moved away from said support to permit said support to descend by gravity toward said work bed, and bring said work tool or point into operative engagement with a printing surface upon said work bed, a cylinder, a plunger slidably mounted therein, 'a vent valve whereby the pressures within said cylinder may be relieved to permit the rapid movement of said plunger in 'one direction, a regulating device adapted to vpermit air to gradually enter said cylinder to regulate the rate of movement of said plunger in the opposite direction, and operative connections between said plunger and said support for the work tool or point, whereby the descent of said support Linder gravity, is controlled, and sufficiently forceful impact of the work tool or point with the printing surface, to mar same, is prevented. j

5. A machine of the character described, embodying'l therein a movable support for a work tool or point, a work tool or point carried thereby, a work bed, means adapted to impart relative universal movement upon a single plane, to said supportand said work bed, a member operative upon said support to move it away from said work bed, means whereby said member may be moved away from said support to permit said support to descend by gravity toward said work bed, and bringr said work tool or point into operative engagement with a printing surface upon said work bed, a cylinder, a plunger slidably mountedi therein, a vent valve whereby the pressures within said cylinder may be relieved to permit the rapid movement of said plunger in one direction, a regulating device open to atmosphere and having a port communicating with the interior of said cylinder, whereby air is permitted to enter said cylinder, and a valve controlling the capacity of said port, whereby the volume of air passing through said port is regulated, to control the rate ofy movement of said plunger in the opposite direction, and operative connections between said plunger and said support for the work tool or point, wherebyv the descent of said support under gravity, is controlled, and

sufficiently forceful impact of the work tool or point with the printing surface, to mar same, is prevented.

6. A machine of thecharacter described,

embodying therein a movable support for av woi'k tool or point, a work tool or point carried thereby, a work bed, means adapted to impart relative universal movement upon a single plane, to said support and said work bed, a member operative upon said support to move it away from said work bed, means whereby said member may be moved away from said support to permit said support to descend by gravity toward said work bed, and bring said work tool or point into operative engagement with a printing surface upon said work bed, a cylinder, a plunger slidably mounted therein, a vent valve whereby the pressures within said cylinder may be relieved to permit the rapid movement of said plunger in one direction, a regulating device adapted to permit air to gradually enter 'said cylinder to regulate the rate of movement of said plunger in the opposite direction, a rod carried by said plunger, a stop mounted upon said rod, and an arm carried by said support, projecting beneath and adapted to engage said stop, whereby the descent of said support under gravity, is controlled, and sufficiently forceful impact of the work tool or 'point with the printing surface, to mar same, is prevented, and movement of said support in the opposite direction, independently of said plunger, is permitted.

7. A machine of the character described, embodying therein a movable support for a work tool or point,`a work tool or point carried thereby, a work bed, means adapted to impart relative'universal movement upon a single plane, to said support and said work bed, a member operative upon. said support to move it away from said work bed, means whereby said member may be moved away from said support to permit said support to descend by gravity toward said work bed, and bring said work tool or point into operative engagement with Ya printing surface upon said workbed, a cylinder, a plunger slidably mounted'therein, a casing carried by said plunger and communication therewith through a port, said casing having a seat about said port, a gravity valve mounted in said casing, cooperating with said seat, whereby the pressure within said cylinder may be relieved to permit the rapid movement of said plunger in one direction, and said port is closed when movement is imparted to said plunger in the opposite direction,

a second casing carried by said plunger having a port communicating therewith, a needle valve carried by said casing, whereby the volume of air admitted to said plunger may be regulated to insure the desired slow rate of movement of said plunger in the opposite direction, and operative connections between said plunger and said support for the work tool or point, whereby the descent of said support under gravity, is controlled, and sufficiently forceful impact of the work tool or point with the printing surface, to mar same, is prevented.

8. A machine of the character described, embodying therein a movable support for a work tool or point, a work tool or point carried thereby, a work bed, means adapted to impart relative universal movement upon a single plane, to said support and said work bed, a member operative upon said support to move it away from said work bed, means whereby said member may be moved away from said support to permit said support to descend by gravity toward said work bed, and bring said work tool or point into op- 'erative engagement with a printing surface upon said work bed, a cylinder,. a plunger slidably mounted therein, a casing carried by said plunger and communicating therewith through a port, said casing having a seat about said port, a gravity valve mounted in said casing, cooperating with said seat, whereby the pressure within said cylinder may be relieved to permit the rapid movement of said plunger in one direction, and said port is closed when movement is imparted to said plunger in the opposite direction, a second casing carried by said plunger having a port communicating therewith, a needle valve carried by said casing, whereby the volume of air admitted to said plunger may be regulated to insure the desired slow rate of movement of said plunger in the opposite direction, a rod carried by said plunger, a stop mounted upon said rod, and an arm carried by said support, projecting beneath and adapted to engage said stop, whereby the descent of said support under gravity, is controlled, and sufficiently forceful impact of the work tool or point with the printing surface, to mar same, is prevented, and movement of said support in the opposite direction, independently of said plunger, is permitted.

9. A machine of the character described, embodying therein a movable support for a work tool or point, a work tool or point carried thereby, a work bed, means adapted to impart relative universal movement upon a single plane, to said support and said work bed, a member operative upon said support to move it away from said work bed, means whereby said member may be moved away from said support to permit said support to descend by gravity toward said work bed, and bring said work tool or point into operative engagement with a printing surface upon said work bed, a resistance device operative upon said support to control the descent thereof under gravity, whereby sufhciently forceful impact of said work tool or point with the printing surface, to mar same, is' prevented, and independent means whereby said support for the work tool or point, and said resistance device, may be adjusted toward, or from, said work bed, to adapt the machine for use upon printing surfaces, the materials of which vary in thickness.

10. A machine of the character described, embodying therein a work bed, a carriage mounted to have universal movement upon a single plane, a yoke carried by said carriage, a frame pivotally mounted within said yoke, the axis of the pivots of said frame extending parallel with said work bed, an arm projecting over said work bed, means whereby said arm is adjustably mounted in said frame, a work tool or point carried by said arm, a transmitter arm, a universal joint connecting said arm with said carriage, a support for said arm intermediate thc ends thereof, a universal joint connecting said transmitter arm with said support, a member operative upon said support to move it away from said Work bed, means whereby said member may be moved away from said support to permit said support to descend by gravity toward said work bed, and bring said work tool or point 100 into operative engagement with a printing surface upon said work bed, and a resistance device operative upon said support to control the descent thereof under gravity, whereby sufficiently forceful impact of said work tool or point with the printing surface, to mar same, is prevented.

l1. A machine of the character described, embodying therein a shelf having tracks thereon, a carriage slidably mounted. on said tracks, a work bed mounted upon said car- 'riage by meansof a slide connection extending` at right angles to said tracks, coperating means carried by said shelf and said carriage, whereby said carriage may be moved along said tracks, coperating means upon said carriage and said work bed whereby said work vbed may be moved upon said carriage at right angles to said tracks, a carriage mounted to have universal movement upon a single plane, a movable support for a work tool or point mounted upon said carriage, a work tool or point carried thereby, means adapted to actuate said universally movable carriage, a member Operative upon said support to move it away from said work bed, means whereby said member may be moved away from said support to permit said support to descend by gravity toward said work bed, and bring said Work tool or point into operative engagement with a printing surface upon said work bed, and a resistance device operative upon said support to control the descent thereof under gravity, whereby sufficiently forceful impact of said work tool or point with the printing surface, to mar same, is prevented.

12. A machine of the character described, embodying therein a work bed, a carriage mounted to have univers/al movement upon a single plane, a movable support for a work tool or point mounted upon said carriage, a work tool or point carried thereby, a transmitter arm, a universal joint connecting one end of said arm with said carriage, a support for said transmitter arm, a universal joint connecting said support with said transmitter arm intermediate the 'ends thereof, means whereby said support may be adjusted toward and from said carriage to vary the operative leverage of said arm, to vary the scale of reproduction, a member operative upon said movable support to move it away from said work bed, means whereby said member may be moved away from said support to permit said support to descend by gravity toward said work bed, and bring said work tool or point into operative engagement with a printing surface upon said work bed, and a resistance device operative upon said support to control the descent thereof under gravity, whereby sufficiently forceful impact of said work tool or point with the printing surface, to mar same, is prevented.

13. A machine of the character described, embodying therein a work bed, a carriage mounted to have universal movement upon a single plane, a movable support for a work tool or point mounted upon said carriage, a work tool or point carried thereby, a transmitter arm, a universal joint connecting one end of said arm with said carriage, a support for said transmitter arm, a universal joint connecting said support with said transmitter arm intermediate the ends thereof, means whereby said support may be adjusted toward and from said carriage to vary the Ioperative leverage of said arm, to vary the scale of reproduction, means whereby said universal joint, connecting said transmitter arm with said support, may be adjusted to vary the operative leverage of said arm in one direction, without varying it in the other direction, to `condense or extend the reproduction, a member operative upon said movable support to move it away from said work bed, means whereby said member may be moved away from said support to permit said support to descend by gravity toward said work bed, and bring said work tool or point into operative engagement with a printing surface upon said work bed, anda resistance device operative upon said support to control the descent thereof under gravity, whereby suiiiciently forceful impact of said work tool or point with the printing surface, to mar same, is prevented.

14. A machine ofthe character described, embodying therein a work bed, a carriage mounted to have universal movement upon a single plane, a pivotal support for a work tool or point mounted upon said carriage, a work tool or point carried thereby, a transmitter arm, a universal joint connecting one end of said arm with said carriage, a support for said transmitter arm, a universal joint connecting said support with said transmitter arm intermediate the ends thereof, means whereby said support may be adjusted toward and from said carriage to vary the operative leverage of said arm, to vary the scale of reproduction, means whereby said support may be tilted to one side or the other, to tilt the reproduction, means whereby said support for the work tool or point may be adjusted radially of its pivots, a member operative upon said support to move it away from said work bed, means whereby said member may be moved away from said support to permit said support to descend by gravity toward said work bed,

and bring said work tool or point into operative engagement with a printing surface upon said work bed, and a resistance device operative upon said support to control the descent thereof under gravity, whereby suciently forcefulvimpact of said work tool or point with the printing surface, to mar same, is prevented.

In witness whereof I have hereunto axed my signature, this 10th day of December,

1918, in the presence of two subscribing witnesses.

WILLIAM S. EATON. Witnesses:

CLARICE FRANCK, F. T. WENTWORTH. 

